ipv6 addrconf hardware type restrictions

[Oliver Hartkopp <socketcan@hartkopp.net>]

Hello,

since the invocation of ipv6_add_dev() at NETDEV_REGISTER time in 
addrconf_notify() i get an 'add_dev failed' when registering a netdevice 
with a MTU of 16.

As the code doesn't check for ipv6 capable hardware types it simply runs 
into an error for some non-ipv6 capable networking hw ...

This patch below may just be a hint - maybe you find any 'nicer' 
implementation for this.

Best regards,
Oliver

Signed-Off-By: Oliver Hartkopp <socketcan@hartkopp.net>

--- addrconf.c-orig    2007-04-26 20:40:38.000000000 +0200
+++ addrconf.c    2007-04-26 20:54:58.000000000 +0200
@@ -2076,15 +2076,6 @@
 
     ASSERT_RTNL();
 
-    if ((dev->type != ARPHRD_ETHER) &&
-        (dev->type != ARPHRD_FDDI) &&
-        (dev->type != ARPHRD_IEEE802_TR) &&
-        (dev->type != ARPHRD_ARCNET) &&
-        (dev->type != ARPHRD_INFINIBAND)) {
-        /* Alas, we support only Ethernet autoconfiguration. */
-        return;
-    }
-
     idev = addrconf_add_dev(dev);
     if (idev == NULL)
         return;
@@ -2172,6 +2163,21 @@
     ip6_tnl_add_linklocal(idev);
 }
 
+static int ipv6_hwtype(struct net_device *dev)
+{
+    if ((dev->type == ARPHRD_ETHER) ||
+        (dev->type == ARPHRD_LOOPBACK) ||
+        (dev->type == ARPHRD_SIT) ||
+        (dev->type == ARPHRD_TUNNEL6) ||
+        (dev->type == ARPHRD_FDDI) ||
+        (dev->type == ARPHRD_IEEE802_TR) ||
+        (dev->type == ARPHRD_ARCNET) ||
+        (dev->type == ARPHRD_INFINIBAND))
+        return 1;
+
+    return 0;
+}
+
 static int addrconf_notify(struct notifier_block *this, unsigned long 
event,
                void * data)
 {
@@ -2179,6 +2185,9 @@
     struct inet6_dev *idev = __in6_dev_get(dev);
     int run_pending = 0;
 
+    if (!ipv6_hwtype(dev))
+        return NOTIFY_OK;
+
     switch(event) {
     case NETDEV_REGISTER:
         if (!idev) {